Rosetta Goes to Sleep

On 8 June, mission controllers will have the first opportunity to switch ESA's Rosetta comet-hunter into deep-space hibernation for 31 months. During this loneliest leg of its decade-long mission, Rosetta will loop ever closer toward comet 67-P, soaring to almost 1000 million km from Earth.

Marking one of the most dramatic and distant stages of the probe's 10-year journey to rendezvous with Comet 67-P/Churyumov-Gerasimenko, ground controllers at ESOC, ESA's European Space Operations Centre, plan to issue the final command next week to switch Rosetta into hibernation mode.

This will trigger the last steps in the shut-down of the spacecraft, turning off almost all flight control systems including telecommunications and attitude control. Rosetta's scientific instruments were already individually powered down during the first four months of this year.  

"Rosetta is getting farther from the Sun, and soon there simply isn't going to be enough sunlight to power its systems," says Paolo Ferri, Head of ESOC's Solar and Planetary Mission Operations Division.…